#!/usr/bin/env ruby

if ARGV.size < 1 then
  puts "#{__FILE__} [options] (log.dat)"
  exit
end
=begin
optionsリスト
ignore <= 無視するヘッダ
only <= このヘッダだけ出力
out <= 出力先、-は標準出力
remove_head <= ヘッダを取り除いて出力
=end

$options = {
  :ignore => "",
}

ARGV.reject!{|arg|
  if arg =~ /--([^=]+)=?/ then
    key = $1.to_sym
    val = $' || true
    case key
    when :ignore then
      $options[key] << val.upcase
    else
      $options[key] = val
    end 
    true
  else
    false
  end
}

in_fname = ARGV.shift
base_fname = $options[:out] \
    || (in_fname.sub(/((?:(?!\.dat).)+)(?:\.dat)?$/){$1} rescue File::basename(__FILE__, '.*'))
$stderr.puts "#{in_fname || '(stdin)'} => #{base_fname == '-' ? '(stdout)' : base_fname}"

class DummyIO
  def write(str); end
  def close; end
end

out_files = {}

read_raw = proc{|io|
  remove_head = $options[:remove_head]
  while page = io.read(32)
    if !out_files.include?(page[0]) then
      if ($options[:only] && (!$options[:only].include?(page[0]))) \
          || $options[:ignore].include?(page[0]) then
        out_files[page[0]] = DummyIO::new
      elsif base_fname == '-' then
        out_files[page[0]] = $stdout
      else
        out_fname = "#{base_fname}_#{page[0]}.dat"
        $stderr.puts "OUT: #{out_fname}"
        out_files[page[0]] = File::open(out_fname, 'w+')
      end 
    end
    if remove_head then
      out_files[page[0]].write page[1..-1]
    else
      out_files[page[0]].write page
    end
  end
}

unless in_fname then
  read_raw.call($stdin)
else
  open(in_fname, 'r'){|io|
    read_raw.call(io)
  }
end

out_files.each{|k, v|
  v.close if v != $stdout
}